Dark-colored system photopolymerized composition

Abstract

A dark-colored system photopolymerization composition, comprising: 20-80 phr of photopolymerizable prepolymer, 5-60 phr of photopolymerizable monomer, 0.2-8 phr of photoinitiator, and 0.1-5 phr of melanin, 0.05-5 phr of upconversion materials. The composition can construct photopolymerization under near-infrared irradiation. The dark pigment can avoid the strong absorption of near-infrared light, and the upconversion material can absorb near-infrared light with good penetrating ability and emit ultraviolet or visible light to induce the decomposition of free radicals or ionic photoinitiators in the composition. Then produced active species realize the photopolymerization of dark-colored compositions. The invention increases the depth of photopolymerization of dark-colored compositions and improves the mechanical properties of the polymer, that will broaden application fields of photopolymerization materials.

What is claimed is: 
     
       1. A dark system photopolymerization composition, comprising:
 photopolymerizable prepolymer 20-80 phr; 
 photopolymerizable monomer 5-60 phr; 
 photoinitiator 2-8 phr; 
 dark pigment 0.1 or 0.3 or 0.5 phr; and 
 upconversion materials 0.05-5 phr, 
 wherein: 
 the photoinitiator is bis 2,6-difluoro-3-pyrrole phenyl titanocene; 
 the dark pigment comprises at least one substance having the following structure: 
 
       
         
           
           
               
               
           
         
         where the range of n is 50-400, and the range of m is 50-400. 
       
     
     
       2. The dark system photopolymerizable composition according to  claim 1 , wherein the photopolymerizable prepolymer and/or the photopolymerizable monomer have a polar group, and the polar group is selected from the group consisting of hydroxyl and amino. 
     
     
       3. The dark system photopolymerizable composition according to  claim 1 , wherein the photopolymerizable prepolymer comprises one or more of polyurethane acrylate, epoxy acrylate, polyester acrylate, and amino acrylic esters. 
     
     
       4. The dark system photopolymerizable composition according to  claim 1 , wherein the photopolymerizable monomer is selected from the group consisting of monofunctional acrylate monomers, bifunctional acrylate monomers, multifunctional acrylate monomers, ester ring epoxy monomers, oxetane monomers, and combinations thereof. 
     
     
       5. The dark system photopolymerizable composition according to  claim 1 , wherein the upconversion material is selected from the group consisting of of NaYF4, BaYF5, NaGdF4, LiYF4, NaYbF4, Na3ScF6, YF3, GdOF, and combinations thereof. 
     
     
       6. A method of making a dark-colored crosslinked polymer comprising polymerizing the dark-colored photopolymerization composition according to  claim 1  under near-infrared light irradiation. 
     
     
       7. The method according to  claim 6 , wherein the wavelength of the near-infrared light is 800-1100 nm; the energy density of the near-infrared light is greater than 1 W/cm 2 , less than 20 W/cm 2 . 
     
     
       8. The dark system photopolymerizable composition according to  claim 1 , wherein the photopolymerizable prepolymer comprises one or more of polyurethane acrylate and epoxy acrylate. 
     
     
       9. The dark system photopolymerizable composition according to  claim 1 , wherein the photopolymerizable monomer is selected from the group consisting of isobornyl acrylate, neopentyl glycol diacrylate, dipentaerythritol hexaacrylate, 1-vinyl-2-pyrrolidone, tetrahydrofuran acrylate, o-phenylphenoxyethyl acrylate, 1,6-hexanediol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexyl formate, and combinations thereof.